P0302

DTC P0300 / P0301 / P0302 / P0303 / P0304: Random / Cylinder 1 / Cylinder 2 / Cylinder 3 / Cylinder 4 Misfire Detected

System Description

ECM measure the angle of the crankshaft based on the pulse signal from the CKP sensor and CMP sensor for each cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes occurrence of a misfire. When the number of misfire is counted by ECM beyond the DTC detecting condition, it determine the cylinder where the misfire occurred and output it as DTC.

DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

WARNING:

- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during testing to avoid occurrence of an accident.
- Road test should be carried out with 2 persons, a driver and tester, on a level road.

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temp.: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Drive vehicle under freeze frame data condition as noted for 1 min. or more.
4) Stop vehicle and check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2.
Does fuel level meter indicate "E" level (empty)?
YES
Add fuel and recheck.
NO
Go to Step 3.

3. Ignition system inspection.

Check spark plug and ignition spark of cylinder where misfire occurs, referring to Ignition System Check Ignition System Check.

Is it in good condition?
YES
Go to Step 4.
NO
Faulty ignition coil, wire harness, spark plug or other system parts.

4. Fuel injector circuit check.

Using sound scope, check each injector operating sound at engine cranking or idling.

Do all injectors make operating sound?
YES
Go to Step 5.
NO
Check coupler connection and wire harness of injector not making operating sound and injector itself.
If OK, substitute a known-good ECM and recheck.

5. Fuel pressure inspection.

Check fuel pressure referring to Fuel Pressure Check Fuel Pressure Check.

Is check result satisfactory?
YES
Go to Step 6.
NO
Repair or replace.

6. Fuel injector inspection.

Check fuel injector(s) referring to Fuel Injector Inspection Fuel Injector Inspection.

Is check result satisfactory?
YES
Go to Step 7.
NO
Replace.

7. Ignition timing inspection.

Check ignition timing referring to Testing and Inspection Ignition Timing Inspection and Adjustment.

Is check result satisfactory?
YES
Go to Step 8.
NO
Adjust.

8. EGR system inspection.

Check EGR system referring to Testing and Inspection EGR System Inspection (Using SUZUKI Scan Tool).

Is check result satisfactory?
YES
Go to Step 9.
NO
Repair or replace.

9. Fuel level sensor inspection.

Check fuel level sensor referring to Step 2 of P0461 DTC P0461: Fuel Level Sensor (Gauge) Circuit Performance Problem.

Is check result satisfactory?
YES
Go to Step 10.
NO
Repair or replace.

10. Engine mechanical systems check.

Check engine mechanical parts or system which can cause engine rough idle or poor performance.
- Engine compression (Refer to Compression Check.)
- Valve lash adjustor (Refer to Camshaft and Valve Lash Adjuster Inspection.)
- Valve timing (Refer to 2nd Timing Chain and Chain Tensioner Removal and Installation
and 1st Timing Chain and Chain Tensioner Removal and Installation.)

Are they in good condition?
YES
Check wire harness and connection of ECM ground, ignition system and fuel injector for intermittent open and short.
NO
Repair or replace.